Note: Descriptions are shown in the official language in which they were submitted.
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This inven-tion relates to a fuel injection arrangement
in an internal combustion engine, the engine preferably being
of the compression ignition type.
~ uel injection nozzles for compression ignition engines
operate at high pressures and therefore need to be secured very
firmly in the cylinder head of an engine. In order to withstand
the high pressure, the fuel supply pipes must be strong and are
made of a relatively inflexible ma-terial. When instal]ing the
fuel injection nozzles, great care must be taken not to impose
an~ undue strain on the supply pipes which could cause leakage
of fuel. To meet these criteria, known constructions make use
of a separate retaining nut which bears against a step defined
in the body of the nozzle and which is screw-threaded into a
bore in the cylinder head of the engine. Such constructions
are however relatively complicated and expensive to manufacture.
According to the present invention, there is provided
a fuel injection arrangement for an internal combustion engine
including a cylinder head having a bore therethrough comprising
a fuel injection device located in said bore, the device
including a housiny having a seating thereon and a valve member
slidable within the housing and co-operating with the seating
to control the flow of fuel from the device in use; a fuel
pipe in ~low communication with the fuel injection device and
having an enlarged end portion; and a retention member in screw
threaded engagement with the cylinder head, the retention
member and the housing having respective abutments thereon
which engage axially opposed parts of the enlarged end portion
of the fuel pipe so as to trap and de~orm the enlarged end
portion therebetween to provide liquid type seals between said
~30 enlarged end portion and said retention member and housing
~ respectively, the retention member also holding the fuel
:
injection device in position in said bore.
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Preferably, said bore i5 stepped and the fuel
injection device is urged into engagemen-t with the step in
the bore by the member acting through the intermediary of the
enlarged end portion.
In one embodiment, the member includes a head portion
and a screw-threaded shank portion which surrounds the fuel
pipe with clearance, the abutment being provided on the head
portion and an end of the fuel injec-tion device being
accommodated within the shank portion.
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In an alternative emho~i.ment, the member include~ a head
por-tion and a ~crew-threaded shank portlon, and the abut~ent
is provided at or adjacent an end of the shank portion remote
from the head portion.
Either or both of the abutments may be ærmed ~y a chamfered
surface.
The enlarged end portiou o~ the fu~l pipe may be formed
by an olive aurrounding the end o~ the pipe9 or may be formed by
the end o~ the pipe being flared outwa~dly.
.
Embodiments of the present invention will now be de~cribed
by way o~ example, with refer2nce to the accompanying drawing~ in
which:-
~igure 1 i5 a sectional qide view af a compre~sion ignition
engine pro~ided with a fir~t embodiment of a fuel injection arranga-
mer~t according to the pre~ent invention,
~igure 2 ~ a sectional side view o~ a compres~ion ignitio~
engine provided with a second embodiment o~ a ~uel injection arrange~
,
ment acco~ding to the pre~ent i~ventionJ and
Figure 3 is a sectlonal side view of a modiPication of the
fuel injection arrangeme~ts ~hown in Figures 1 a~d 2.
Refarring to Figure 1 the fuel injection arrang0ment show~
therein~comprises a ~uel injection de~ice 10 located in a bore 11
,
in a cyllnder head 12 of the eng.ine and engaging a ~tep 13 in the
;~ ~ bore 11 through the intermediary of a sea~ing wa~her 13a~ T~e
injection device 10 include~ a housing 14 formed in *wo parts 15,
16 which are mutually ~ealingly engaged and which de~ine a chamber-
in the housing 1~ . The housing part 15 has a fuel inlet opaning 17
therein communicating with the chamber, and the ho~lsing part 16 .
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_Aei.~iil, ......... ~ .... . ._L. l~C3s,tf'~1¢3'~; ...
ha~ an axial bore therein in ~*lich a poppet valve member
18 i9 slidably hou~edO A head of the member 18 co~operateis.
with a seating 19 on th~ housin5~, part 16 to control the
flow of fuel into a combu3tion chamber 20 o~ the engine
into which the nS~rrower end oP the bore 11 open3.
A stsm of mernber 18 isS 80 sized relative to the bore i~s
hou~lng part 16 that an annular s~Space is3 defined between
the stem and the side wnll of th0 bore, whlch space communicato~ i
with the chamber via openinge 21 in th0 houslng part 16. A .
collar 22 is9 provided on tha stem and ha~ helical ~rooes *heroin, .:::
the groo~es3 aoting to impart a swirling motion to the fuel asS
it i8 e~ected ~rom the in~ection deYice 10 to enhance atomiS3a-
tion o~ the ~uel. The ope~ation o~ thi~ form of in~ection
devlce i~ well know~, and will not ba described f~rther. An :~:
end c~ the valva member 18 remo*e from the head thereo~ ha~
a spring, abutment 23 mounted thereonf and a s~pring 24 i~
accommod~edln the houssing ahamber between the spring
abutme~t 23 and the housing part 16 the spring 24 acting to ¦
oppose lifting o~ the ~a~e member 18 off the ~eating 19.
~ 20 The fuel in~ection arrangcment ~urther oompr~f3efs a
: ~ ~uel supply pip0 Z6 whose end if3 enlarged b~ mean~s of an~ !
oli~ 27, and a screw-threaded member 28 ha~ing a central
opening through ~hich the pipe 26 pass~s~ The me~ber
28 include~ ~ head portion 29 and a shank portlon 30 ,
integral therew~th which i~ ~cr~w-threaded on its external
i
~urfaoe and which engages corresponding ~crew-threading
I ~ on the ~ide ~all o~ bore 11, ~n end of the shan~ portion
30 remote ~rom the head portion 29 i5 chamfered 80 a~ to
deflne a~ abutment 31~ The hou~ing 14 of the ~uel 1.
.
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injection df~fvice lO is also chamfered in the region of
the inlet opening 17 so aq to de~irlf3f a further abutmf_fnt
32. The abutments 31, 32 ff-ffngage axially opposed parts of
the oli~e 27, f~O that the end of the pipe Z6 i~ trappefd
therebetween, the pipe 26 thfefreby being h01d in flow
f~o~mfunication with the inlet opening 17fff Liquid tight
seala between the member 28 and the olive 27 on the o~e ha~d,
a~d between the housi~g 14 and the ollvf~f 27 on the other
hand are produced by de~ormation of t~3f oli~ffff 27 as the
member 28 i~ screwed down.
From the above, it will be appreciatf3fd that the scrafw-
threaded member 28 not only fser~e~ to connect the pip~
26 to the in~ection de~lca lO 9 but alqo ser~ef~f to hold
the injection davice lO in position in the bOrf3f 11 by
acting on thfs olive 27 and, throufgh the intermediary o~
the latter, urging the device lO into engagemant with ~hfsf
stop 13 in the borff,11~
The fuff~fl injection arrangement qhown in Fifgure 2
is similar to that de_rribed abo~e in rfPflation to Fisurf~f l~f .
~imilar part3 being accorded tha qame re~erenc~f numerala with
~,,
~ 100 addedffff I~ thifq~ 0mbodiment~ ho~ffqfver, the ~hank portiafn 130
. ~ ~
o~ the screw-threaded ~fember 128 f~furrounds *hfFff e~d of the fuel
.~ inilectlon f~e~ioe llO fand the bOrf3lll i9 furthf~fr ~teppfsffd to
J accf~fm~.odate the threafded membef~ff~ The olivs 127 is trapped
between the abutment t3Z on the hou~ing ~ff~ of the fufsl inJection
e~icef 110 and an abutwent 133 on thf3f head portion 12~f o~ the screw- .
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threaded member 128.
From a comparison of Figures 1 arJd 2 it will be
appreciated that the arrangement of Fiyure 2 occupies less axial
space in the cylinder head than that of Figure 1.
A modification of the above described arrangement is
; illustrated in Figure 3. In the embodiments of Figures 1 and
2, sealing between an end of the housing part 15, 115, and the
step 13, 113 in the bore 11, 111 is effected by means of the
sealing washer 13a, 113a. ~owever, this form of arrangement
can be replaced by that shown in E'iy~lre 3, in which the end
of the body part (referenced 150) is radiussed and engages
the seat ~referenced 151) directly. The seat itself is of
spherical or substantially spherical form and its radius of
curvature is greater than the radius o~ the end of the body
part, so that the body part and the seat can be mutually
sealingly engaged.
In a m~dified arrangement tnot shown) the olive is
omitted and the end of the fuel supply pipe 26, 126 is enlarged
by flaring the wall thereof outwardly.
The constructions described obviate the need to provide
two separate arrangements for securing the pipe to the housing
~ and for securing the device within the bore. ~s a result
;, there is an economy of parts and the axial length of the injec-
l tion devicecan be made smaller.
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